The present invention relates to a vehicle hydraulic braking system and, more particularly, to an anti-skid braking device for controlling braking force when deceleration of a braked wheel exceeds a predetermined value.
In one prior art anti-skid braking device, braking pressure is controlled by means of an electromagnetic valve which is actuated by an electric signal issued from a detecting device sensitive to rotational speed or rate of variation in rotational speed of the braked wheel. In another prior art device, the inertia force of a flywheel or a governor driven by the braked wheel is utilized to actuate a mechanical valve which is operable to reduce braking pressure or to by-pass braking fluid to a reservoir.
The disadvantage of these prior art devices are such that the entire system incorporating such devices becomes complicated when the system utilizes the electric signal, and that the overall dimensions of the valve mechanism become large when a governor or the like has been incorporated therein.